Onium salt, photopolymerization initiator, energy ray-curing composition containing the initiator, and cured product

Abstract

The composition of the present invention is excellent in compatibility, transparency and curability and give a cured coat of excellent gloss and of less smell, and cured products of excellent properties can be obtained by curing the composition. The present invention relates to an onium salt represented by the following formula (1): ##STR1## wherein Ar is a mono- to tetra-valent aromatic group, X is a bisphenylsulfonio group which may have a substituent, a is 1-4, b is 0 or 1-3, a+b is 1-4, n is 1-4, and Z is a halide represented by the following formula (3): MQ.sub.m (OH).sub.l (3) where M is a boron atom, a phosphorus atom, an arsenic atom or an antimony atom, Q is a halogen atom, m is 3-6, l is 0 or 1, and m+l is 4-6; a photopolymerization initiator containing the onium salt as an active ingredient; an energy ray-curable composition containing the initiator; and a cured product.

What is claimed is: 
     
       1. An energy ray-curable composition which contains a cation polymerizable substance and an onium salt represented by the following formula (1): ##STR32## wherein Ar is ##STR33##  which may have at least one substituent selected from (C 1  -C 5 ) alkyl group, (C 1  -C 5 ) alkyloxycarbonyl group, (C 1  -C 5 ) alkylcarbonyloxy group, benzoyl group, cyano group, (C 1  -C 5 ) alkylthio group and halogen atom; X is a bisphenyl-sulfonio group represented by the following formula (2): ##STR34## wherein R 1  -R 10  each is a hydrogen atom, a halogen atom, a nitro group, an alkoxy group, an alkyl group, a phenyl group which may have a substituent of C 6  -C 18 , a phenoxy group, a phenylcarbonyl group, an alkylthio group, a phenylthio group, a benzyloxy group, a C 1  -C 25  aliphatic group containing at least one hydroxyl group or a C 3  -C 25  aliphatic group containing a group represented by the following formula: ##STR35## where R 11  is a hydrogen atom or an alkyl group; a is 1-4; b is 0 or 1-3; a+b is 1-4; n is 1-4; and Z is a halide represented by the following formula (3):   MQ.sub.m --(OH).sub.l                                      ( 3)     where M is a boron atom, a phosphorus atom, an arsenic atom or an antimony atom, Q is a halogen atom, m is 3-6, l is 0 or 1, and m+l is 4-6.   
     
     
       2. A composition according to claim 1 wherein the cation polymerizable substance is an epoxy compound, a vinyl ether compound or a cyclic ether compound. 
     
     
       3. A composition according to claim 2, wherein the epoxy compound is an alicyclic epoxy resin. 
     
     
       4. A composition according to claim 2, wherein the vinyl ether compound is triethylene glycol divinyl ether, tetraethylene glycol divinyl ether, cyclohexane-1,4-dimethyloldivinyl ether, 1,4-butanedioldivinyl ether, ##STR36## or urethane polyvinyl ether. 
     
     
       5. A composition according to claim 1, wherein the onium salt is represented by the following formula: ##STR37## 
     
     
       6. A composition according to claim 1, wherein the energy ray is an ultraviolet ray. 
     
     
       7. A composition according to claim 1 which comprises 100 parts by weight of the cation polymerizable substance and 0.01-20 parts by weight of the onium salt. 
     
     
       8. An ultraviolet ray-curable composition which comprises 100 parts by weight of an alicyclic epoxy resin and 0.1-10 parts by weight of the onium salt represented by the following formula: ##STR38## 
     
     
       9. An ultraviolet ray-curable composition which comprises 100 parts by weight of a vinyl ether compound and 0.1-10 parts by weight of the onium salt represented by the following formula: ##STR39## 
     
     
       10. A composition according to claim 9, wherein the vinyl ether compound is triethylene glycol divinyl ether, tetraethylene glycol divinyl ether, cyclohexane-1,4-dimethyloldivinyl ether, 1,4-butanedioldivinyl ether, ##STR40## or urethane polyvinyl ether. 
     
     
       11. A composition according to claim 1, wherein the onium salt is represented by the following formula: ##STR41## 
     
     
       12. An ultraviolet ray-curable composition which comprises 100 parts by weight of an alicyclic epoxy resin and 0.1-10 parts by weight of the onium salt represented by the following formula: ##STR42## 
     
     
       13. An ultraviolet ray-curable composition which comprises 100 parts by weight of a vinyl ether compound and 0. 1-10 parts by weight of the onium salt represented by the following formula: ##STR43##